1. Field of the Invention
The invention relates to a method for testing devices of mobile-radio systems, devices provided for this purpose, a signal generator and a measuring system.
2. Discussion of the Background
For the testing of mobile radio systems, a so-called protocol tester is conventionally used. This protocol tester communicates via a standardized radio connection with a device of the mobile-radio system, that is to say, a base station or a mobile-radio device. For the test, a standardized connection of this kind is established with so-called uplink and downlink signals between the device under test and the protocol tester. During an early developmental stage, analysis of a device under test by means of a protocol tester is often not yet possible, because all of the functions prescribed in the respective mobile-radio standard have not yet been implemented. Moreover, the protocol testers are qualitatively inferior to a signal generator with regard to the quality of a transmitted high-frequency signal. Accordingly, in the development of devices for mobile-radio systems, it is often desirable to test the behavior of the device under test by means of a signal generator. These tests include test cycles, which are adapted, for example, to a test loop to be implemented subsequently in the production stage.
A signal generator, with which a high-frequency signal corresponding to a selected mobile-radio standard can be generated and transmitted, is known, for example, from DE 101 24 371. The signal generator can generate a standardized high-frequency signal and transmit it over a radio path to a device under test, however, no return channel is set up between the signal generator and the device under test. This signal generator provides a signal-generating portion, a transmission portion and a control portion. A signal, which is generated within the signal-generating portion, is transmitted by means of the transmission portion. The generation of the signal including the signal data, upon which the signal to be generated and transmitted is based, is controlled in this context by a control portion of the signal generator.
Accordingly, it is, on one hand, possible to generate a high-quality transmission signal, but, on the other hand, the use of a signal generator has the disadvantage that a corresponding reception device for processing the response signal transmitted from the device under test via a return channel, also in conformity with a mobile-radio standard, is not provided.